Let-off mechanism.



W. STRITTMATTER & H. SCHIMMEL.

LET-OFF MECHANISM.

APPLICATION FILED NOV. 10. ms.

Patented J uly 10, 1917.

INVENTOR,

um STrfiTmaTYer UNITED STATES PATENT OFFICE.

WILLIAM STRITTMATTER AND HERMAN SCHIMMEL, OF WEEI'IAWKEN, NEW JERSEY.

LET-OFF MECHANISM.

Application filed November 10, 1916.

To all whom it may concern:

Be it known that we, IVILLIAM STRITTMAT- TER and HERMAN SGHIMMEL, citizens of the United States, residing at WVeehawken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Let-Off Mechanisms, of which the following is a specification.

The object of this invention is to provide a simple, compact, and reliable let-off mechanism for looms whereby the warp will be allowed to be delivered only with uniformity and smoothness and entirely without any jerkiness such as characterizes ordinary letoff mechanisms and due principally to the braking means being formed with brakeshoes or brake-straps or otherwise offering extended surfaces and therefore sticking to the warp-beams. According to this invention, the braking means is a warp-controlled lever whose braking surface is preferably convextherefore offering limited contactand is disposed relatively between the fulcrum of the lever and the warpbeam,-being in the preferred form composed of some such yielding material as rubber or the like.

In the accompanying drawing,

Figure l is a side elevation of the let-off mechanism;

Fig. 2 a side elevation, on a larger scale, of the adjoining portions of the brake-lever and warp-beam, the latter appearing partly in section; and,

Fig. 3 is a sectional view on line 33 of Fig. 2.

a is a part of the loom frame, Z) the warpbeam, 0 a bar overwhich the warp A extends on its way from the warp-beam to the take-up mechanism (not shown), d the brakelever and e a bracket in which the warp-beam is journaled and the brake-lever fulcrumed in the manner to be explained.

The end of the brake-lever which adjoins the warp beam is convex, as at f, and comprises a pad f of rubber or other yielding material which will afford good braking contact with the periphery of the warp-beam, being convex in cross section (Fig. 3) so as to conform more or less to the groove in the periphery of the warp beam. Such pad is not indispensable, though it is preferred. Said end of the lever offers a braking surface which is limited, by being convex, and is further disposed relatively between the fulcrum of the lever and the warp-beam. It will therefore be seen that if the lever is Specification of Letters Patent.

Patented July 10, 1917.

Serial No. 130,569.

moved one way (the direction in which the warps tend to pull it) it will ultimately clear the warp-beam; whereas if moved the other way (the direction in which gravity moves it) it will return into position to bind against the warp-beam. In actual use, by properly weighting the lever the action of gravity and the pull of the warp may be made so nicely to substantially balance each other that there is practically a merging of the conditions of grip and release of the brake-lever with respect to the warpbeam, so that the warp responds to the pull of the take-up mechanism wholly without jerkiness in even the slightest degree. The free end of the lever is equipped with a roller tZ under which the warp passes, and a weight or weights d.

In order that the brake-levers may be adapted to fall back in letting back the fulcrum stud g of the lever is arranged in a slot h in the bracket 6, said slot extending away from the warp-beam in approximately the same direction that the fulcrum stud g is from the axis of the warp-beam, and the end of the lever which adjoins the warpbeam has its convex braking face 7 formed as a parabolic curve whose focus is the fulcrum stud 9. Thus when the lever falls in letting back its braking end continues to hold the beam against turning, stud g, on ac count of the parabolic curve of face 7, moving outwardly in slot it as the lever desc-ends;'for limiting this movement of the lever, the stud g is adapted to come against the stop it of the slot, the braking end of the lever still of course continuing to hold the beam securely against turning.

Quite aside from this detail, however, we desire to point out that so far as we are aware it is new in a let-off mechanism to provide a brake-lever which, being pivotally movable back and forth in response to the counteracting influences of gravity and the pull of the warp, is movable in the fulcrum support therefor substantially longitudinally of itself, being normally held against the warp-beam by the force which is the resultant of those influences.

In order that the brakelever may be moved to a position where it is entirely stud 9, so that the lever may be shifted in the guideway thus formed to its end 70 and hang pendent therefrom.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is 1. In combination, a supporting means, a warp-beam journaled therein, and a warpactuated brake-lever fulcrumed in said supporting means and having means to be engaged by the unwound portion of the warp extending from the beam and also having a convex braking face at the warp-beam side of its fulcrum.

2. In combination, asupporting means, a warp-beam. journaled therein, and a warpactuated brake-lever fulcrumed in said sup porting means and having means to be engaged by the unwound portion of the warp extending from the beam and also having a yielding convex braking face at the warpbeam side of its fulcrum.

3. In combination, a supporting means, a warp-beam journaled therein, and a warpactuated brake-lever fulcrumediin said supporting means and having means to be engaged by the unwound portion of the warp extending from the beam and also having a convex braking face at the warp-beam side of its fulcrum, said lever being bodily shiftable in approximately the same direction as Copies of this patentmay be obtained for its fulcrum is from the axis of the warp beam.

4. In combination, a supporting means, a

warp beam journaled therein, and a brakelever fulcrumed in said supporting means and having a braking face at the warp-beam side of its fulcrum, said supporting means having a fulcrum guideway for the lever extending in a line from the warp-beam.

5. In combination, a supporting means, a

warp-beam engaged by the brake-lever, said brakelever being free to move substantially longitudinally of itself in the supportlng' means toward and from the warp-beam and being normally held against the warp-beam by gravity and the warp.

In testimony whereof we aflix our signatures.

WVILLIAM STRITTMATTER. HERMAN SOHIMMEL.

five cents eaclnrby addressing the Commissioner of Patents. Washington, D. C. 

